Figure 1: Effect of grape seed extract on leucocytes thiobarbituric acid reactive substances (TBARS). Treatment with the pure catechin (CS to a final concentration of 310 µM/mL medium) and grape seed extract (PE to a final concentration of 35 µg polyphenols/mL medium) was administrated at the initiation of the culture (3 hrs and 24 hrs for 3 hrs) and at 24 h (24 hrs). Leucocyte thiobarbituric acid reactive substances were assessed 4 h (3 hrs) and 24 h (24 hrs for 3 hrs) after adding the polyphenols (CS and PE) for the same cell sample and at 25 h (24 hrs) for another one. Data are presented as mean ± S.E.M. Values are expressed as percent of control for the experimental variants tested: LS-standard lipoxygenase, LE-lipoxygenase extract, CS-catechin standard, and PE-polyphenolic extract.